Autoregressive Models of Amplitude Modulations in Audio Compression

We present a scalable medium bit-rate wide-band audio coding technique based on frequency domain linear prediction (FDLP). FDLP is an efficient method for representing the long-term amplitude modulations of speech/audio signals using autoregressive models. For the proposed audio codec, relatively long temporal segments (1000 ms) of the input audio signal are decomposed into a set of critically sampled sub-bands using a quadrature mirror filter (QMF) bank. The technique of FDLP is applied on each sub-band to model the sub-band temporal envelopes. The residual of the linear prediction, which represents the frequency modulations in the sub-band signal, are encoded and transmitted along with the envelope parameters. These steps are reversed at the decoder to reconstruct the signal. The proposed codec utilizes a simple signal independent non-adaptive compression mechanism for a wide class of speech and audio signals. The subjective and objective quality evaluations show that the reconstruct...

• Type: Journal
• Year: 2010
• Where: TASLP
• Authors: Sriram Ganapathy, Petr Motlícek, Hynek Hermansky
• Keywords: Audio Codecs, Audio Signals, Bit-rate Wide-band Audio, Software Engineering, TASLP 2010